Expand type checking to the whole src folder

[tsusanka]

Currently we run mypy on src/main.py, which means not everything in the src folder is being tested by mypy.

[mmilata]

Would be also nice to generate HTML report when running mypy: https://mypy.readthedocs.io/en/stable/command_line.html#report-generation

And perhaps fail CI if type coverage falls bellow threshold like we do for test coverage?

[tsusanka]

I totally agree! Maybe we can add the CI check already? So we make sure the coverage does not degrade.

[mmilata]

In the current state the report only shows main.py which is not very useful:) Passing all .py files to mypy makes it print a lot of warnings so we'd have to sort through all of them. I can look into it, maybe there's a way to generate reports for the set of files we currently check, then we can gradually expand this set ...

[tsusanka]

It was nonsense. I was thinking about adding a CI job to check if the current mypy coverage did not degrade but we obviously already have that - it is part of make style_check.

[matejcik]

mostly fixed via #1939

what remains is the Monero app, for which I'm keeping this issue open

[hynek-jina]

Monero remains to be done